Proton MRS of Bilateral Substantia Nigra in the Human Brain at 4 Tesla with Hadamard Encoding
Oz G, Gruetter R, Tkac I, Lowary J, Tuite P
University of Minnesota
Substantia nigra (SN) is the primary affected brain region in Parkinsons disease. 1H MR spectra were acquired at 4 tesla simultaneously from two voxels (2.2 ml VOI) encompassing the right and left SN of ten healthy volunteers using Hadamard encoding, excluding central CSF spaces. The neurochemical profile including GABA, glutamate and glutathione was quantified using LCModel in individual subjects. Significantly higher GABA and lower glutamate concentrations relative to reported cortical values were measured, in good agreement with single voxel spectroscopy of the unilateral SN and neurochemistry literature. No right-left asymmetry was observed.